Method for killing grassy and broadleaf weeds

ABSTRACT

A HERBICIDAL COMPOSITION COMPRISING AS AN ACTIVE INGREDIENT A THIOCARBAMINATE COMPOUND OF THE FORMULA   R-CO-S-CH2-R&#39;&#39;   IN WHICH R IS SELECTED FROM GROUP CONSISTING OF MONOALKYLAMINODIALKYLAMINO, PIPERIDINO AND MORPHOLINO RADICAL AND R&#39;&#39; IS A HALOGENATED PHENYL.

United P t fl U.S. Cl. 71 --ss 9 Claims ABSTRACT OF THE DISCLOSURE A herbicidal composition comprising as an active ingredient a thiocarbamate compound of theformula R+3SCH2R' in which R is selected-from group consistingof monoalkylaminodialkylamino, piperidino and morpholino radical and R is a halogenated phenyl.

This is continuation of application Ser. No. 651,148, filed July 5, 1957, now abandoned.

The present invention relates to herbicidal compositions containing S-halobenzyl-thiocarbamates having the Patented June 1, 1971 toxicity to paddy rice plant and can prevent exactly wire grass, has never been discovered.

The reason why, wiregrass has been unusually grown in paddy, is based on the fact that in general, the previous herbicidal compositions are spread'3 to 7 days after the rice plant is planted, while generation of wiregrass is about 2 weeks after planted, that is, wiregrass is generated following general formula as an active ingredient and a method for combatting weeds b using the above described S-halobenzyl-thiocarbamates as the active ingredient.

' The S-halobenzyl-thiocarbamates used herein have the general formula I R-C-S-CHr-R e wherein R is halophenyl group and R is monoalkylamino, dialkylamino, piperidino or morpholino group.

I S-halobenzyl-thiocarbamates according to the present invention are active as herbicidal composition and have a high activity for controlling germination of various weeds in agricultural field and particularly, said compounds can prevent wiregrass (Eleocharis acicula'ris when the activity of the herbicidal compositions are decreased and further wiregrass is perennial, so that it has high resistance against the herbicidal composition.

The most active composition for preventing wiregrass has been DBN (active ingredient: 2,6-dichlorobenzonitrile), but this composition is highly phytotoxic against paddy rice plant, so that it has problem in practice.

However, the S-halobenzyl-thiocarbamates according to the present invention are excellent in the activity for preventing wiregrass and particularly, when they are used in an original stage of growth of wiregrass, wiregrass is completely prevented in an amount of less than 500 g./ 10 ares. Particularly, when surface layer of soil or water field paddy is applied with 250 g./ 10 ares before germination of the weed, the growth of the weeds, such as,wiregrass, barnyard grass and crabgrass, etc., can be prevented and paddy rice plant planted in a depth of more than 2 cm. is not damaged. When 800 to 1,000 g./l0 ares are used, the growth is slightly suppressed temporarily but hereafter is not affected and these compounds have substantially no damage.

Furthermore, when S-halobenzyl-thiocarbamates according to the present invention are used with PCP (pen.- tachlorophenol) or its salts in combination, various therophytic weeds including perennial weed of wiregrass can be completely prevented. Furthermore, a high herbicidal activity can be obtained in an amount of to /5 the amount when both the compounds are used solely and an apparent synergistic effect can be recognized. The

' most effective range of the mixture ratio of S-halobenzylthiocarbamates to PCP is 120.5 to 10 by weight, when S- -halobenzyl-thiocarbamates are combined with PCP.

'- in the following.

Roem. et Schult), barnyard grass, (Echinochloa crus -gwlli P. Beauv) and crabgrass (Digitaria adscendens HenrQ), which are main noxious'weeds in paddy.

Herbicidal composition applied previously to paddy have involved PCP, NIP (active ingredient: 4-nitro-2',4"-

dichlorodiphenyl ether), Prometryne (active ingredient:

Z-methylthiov 4,6 bis(isopropylamino)-S-triazine)--and other, numerous compositions, but most of them have been used for controlling germination of weeds after paddy rice plant is planted. These previous-herbicidal compositions are elfective-for therophyte weeds generated at a relatively earlystage after planting the rice plant, but have extremely poor activity or substantially no activity for wiregrass of perennial weed. Recently, this wiregrass has become a problem as preferential weed in paddy, be-

cause any herbicidal composition, which has no phyto- Halobenzyl mercaptan is dissolved in an inert solvent such as toluene or benzene and to the resulting solution is. added'dropwise a solution of phosgene in an inert solvent and the resulting mixture is stirred while cooling and added with a hydrochloride acceptor dropwise. Then, the resulting mixture is added dropwise with monoalkylamine or dialkylamine and the mixture is reacted. In order to remove hydrochloride ofthe hydrochloride acceptor (amines) after .completion of the reaction, the reaction product is washed with water, dried and concentrated.

Furthermore, the resulting liquidis purified by vacuum distillation.

This process is shown by the following reaction formulae.

II RCHzSOR Base H01 1 S- (2-chlorobenzyl) -N-methylthiocarbamate (2) S-(4-chlorobenzyl)-N,N-diethylthiocarbamate (3 'S- (Z-bromobenzyl) -'N,N-diisopropylthiocarbamate (4) S-(2,4-dichlorobenzyl)-N,N-diisopropylthiocarbamate (5 S- (4-chlorobenzyl) -piperidino- 1 -carbothioate 6) S- 3 ,4-dichlorobenzyl) -morpholino-4-carbothioate An example of the production will be mentioned as follows: A

I A solution of 31 g. (0.2 mol of 4-chlorobenzylmercaptan in 100 ml. of toluene was mixed with 70 g. (about 0.2 mol) of 30% solution of phosgene in toluene To the resulting mixture were added dropwise 24.2 g. (0.2 mol) of dimethylaniline, while stirring by cooling with ice at a temperature of lower than 5 C. After addition of said dimethylaniline, the mixture was stirred for one hour while maintaining such a condition and was added dropwise with 29.2 g. (0.4 mol) of diethylamine at a temperature of lower than C. Furthermore, the resulting mixture was stirred at room temperature for one hour and then at about 60 C. for 3 hours and the reaction was completed and then the temperature was returned to room temperature.

After the reaction, the amine chloride was removed by washing with water and organic layer was dried with anhydrous Glaubers salt and then concentrated. The resulting liquid was purified by vacuum distillation to obtain 41 g. (yield: 79.5%) of a transparent liquid having a boiling point of 128 to 135 C./O.2 mm. Hg and a refractive index of n =1.5632.

Elemental analysis-N (percent): Calculated value, 5.43; found value 5.28.

In addition, the other compound can be produced in the same manner as described above.

S-halobenzyl-thiocarbamates according to the present invention are mixed with diluents involving carriers and surfactants to prepare dust, emulsifiable concentrate and wettable powder, which are used directly or after diluted with water as herbicidal compositions.

Furthermore, said 'carbamates can be prepared into granular composition. Namely, said thiocarbamates are increased in an amount with bentonite, clay, talc, lime stone, etc. and added with a binder, such as, PVA (polyvinyl alcohol) and the resulting mixture is kneaded with water and subjected to an extrusion type of granule forming machine and the formed granules are dried. Alternatively, said thiocarbamates are dissolved in a proper solvent and the solution is homogeneously adsorbed into granular diatomaceous earth, vermiculite, etc. As the other means, by said thiocarbamates is coated surface of granular lime stone uniformly. The granules thus obtained are dispersed uniformly by hand, granule spreader, helicopter, etc.

The term carrier used herein means carrying agents used for transferring said thiocarbamates to desired areas, which may be solid or liquid. For example, as the solid carrier, mention may be made of various clays, talc, kaoline, diatomaceous earth, calcium carbonate, white carbon, saw dust, etc. As the liquid carrier, use may be made of a solvent for the active ingredient or a liquid which is non-solvent, but can disperse or dissolve the active ingredient through an adjuvant, for example, water, benzene, kerosene, alcohol, acetone, methylnaphthalene, xylene, etc.

The term surfactants used herein means unionic surfactants, such as, polyoxyethylenealkylaryl ether, polyoxyethylenesorbitane monolaurate, etc.; cationic surfactants,

such as alkyldimethylbenzyl ammonium chloride, alkylpyridinium halide, etc.; anionic surfactants, such as, alkylbenzene sulfonates, fatty alcohol sulfates, etc.; amphoteric surfactants, such as, lauryl amine derivatives, betaine derivatives, dodecyl diaminoethyl glycine, etc.

The invention will be further explained in detail with reference to the following preparation examples:

EXAMPLE 1.-WETIABLE POWDER Twenty-five parts by weight of S-(2-chlorobenzyl)-N- methylthiocarbamate, 10 parts by weight of white carbon, 60 parts by weight of diatomaceous earth and 5 parts by weight of wetting agent of a mixture of polyoxyethylenealkyl phenol ether, polyoxyethylenephenylphenol ether and polyoxyethylene carbonate were mixed and milled and the resulting powder was suspended in water, which was sprayed.

'EXAMPLE 2.GRANULE Five parts by weight of S-(4-chlorobenzyl)-N,N-diethylthiocarbamate were sprayed on and adsorbed inparts by weight of granular diatomaceous earth, which was being stirred and had 10 to meshes.

EXAMPLE 3.-EM'ULSIFI ABLE CONCENTRA'IE Fifty parts by weight of S-(4-chlorobenzyl)-N,N-diethylthiocarbarnate, 30 parts by weight of xylene and 20 parts by weight of an emulsifier of a mixture of polyoxyethylenealkylphenol ether, polyoxyethylenephenylphenol ether and polyoxyethylene carbonate were mixed and dissolved. The resulting solution was diluted with water and then sprayed.

EXAMPLE 4.GRANULE 1 Seven parts by weight of S-(4-chlorobenzyl-N,N-diethylthiocarbamate, 10 parts by weight of PCPsodium salt, 10 parts by weight of diatomaceous earth, 40 parts by weight of bentonite, 30 parts by weight of clay, 2 parts by weight of sodium alkylsulfonate and 10 parts by weight of PVA were mixed and milled and added with a suitable amount of water and the resulting mixture was kneaded and then subjected to an extrusion type of granules forming machine (open having 1 mm. diameter) to form granules which were dried.

EXAMPLE 6.WE'ITABLE POWDER Twelve point five parts by weight of S-(4-chlorobenzyl)- N,N-diethylthiocarbamate, 25 parts by weight of PCP, 30 parts by weight of clay, 29.5 parts by weight of diatomavceous earth, 1 part by weight of polyoxyethylenealkylaryl ester and 2 parts by weight of sodium ligninsulfonate were mixed and milled to obtain a wettable powder.

In order to show the activity of the herbicidal compositions of the present invention, experimental examples are described as follows:

Experimental Example 1 Three groups of 3-leaf stage young paddy rice plant (species: Kinmaze), one group of which has two rice plants, were planted in a pot of 15 cm. diameter. After the rice plant took, 30 barnyard grass seeds per pot were sowed on the surface layer of the soil and the pot was filled with water to a depth of 1 cm. and one day later granular compositions containing 5% active ingredients of the present invention (Example 2) were spread'in such amounts that the amounts of active ingredients were 100 g.,250 g. and 500 g. per 10 ares. Two weeks after treatment, the growth degree or the weed and the phytotoxicity on the paddy rise plants were estimated. 7

Number of Nliinbei: I v barnot p m Dose yard broad Phytotoxicity Actlvfe gram! grass leaf on paddy rice ingredient 10 ares plants weeds plant Compound 1; 500 '0 9 No damage.

250 1 2 Do. 100 5 11 Do;

Compound 2'; 500 '0 Do. 250 0 1 D0. 100 2 1 .Do.

Compound sit-1...- 500 o 0 Do. 250 0 3 Do. 100 1 5 Do.

Compoundiwutn 0 Do. 250 0 2 D0. 100 2 9 D0.

Compound 5. 500 0 0 Do. 250. 0 1 D0. 100 3 7 D0.

Compound 6-. 590 0 0 Do. 250 1 3 D0. 100 4 6 D0.

S-benzyl-N, N-

diethylthiocarbamate (compara- V r v tive compound; 500 1 4 Heavy damage. 250 4 8 Slight damage. 100 7 13 No damage.

i ion-treated 0 Experimental Example 2 pot of diameter filled with upland soil and wheat and radish seeds were sowed in the pot and then the pot was covered with soil in a depth of 2 cm.

in this ease, the covering soil had been previously mixed with ciab'gr'ass seeds. one d'ay aftjei' "covering the pot with soil, the suspensions obtained by diluting the Wet'table powders having 50% of the active ingredients with ml. of water in such a manner that the given amounts as shown in the following tablewere applied, were sprayed uniformly on the soil surface. The determination was inade three weeks after the spraying.

'Crab grass (g a s) nose, a 10 ares Wheat, Radish Active ingredient Compound 1 illi- Compound2 IIH- llH-

Compound 3 Compound 4 Compound 5 Compound 6 Non-treated 0 z a v Note.-=No damage; i=Very slight damage; +.=Slight damage.

Experimental Example 3 A pot of 15 cm. diameter was fed with paddy soil containing wiregrass root and then filled with water, Two days after the filling the suspen'sion's obtained by diluting the wettable powders having of the active ingredients with 5 ml. of water in such a manner that the given amounts as shown in the following fable were applied, were dropped on the pot and the thus treated pots were left to stand in a greenhouse. Two weeks after the treatment, the growth state of wiregrass was estimated and Weight State of living two plant Dose, weeks" o'nemonth gram] after after treated Active ingredient 10 acre treated (grams) Compoundl 100 0.8 250 0.01

compon'nda--. 100 1.0 250 0.1

compound; 100 1.3 250 i 0.3

Compoundfi 500 0.7 250 :i: 0.2

com ounded 50o 1.2 250 :i: 0.3

Non-treated r. s Note.'--=No growth; =|==Sllght growth; +=Moderate growth;

# '=-Heav'y growth; =Very heavy growth.

Experimental Example t A pot of 15 em. diameter was fed with paddy soil and planted with three groups of young paddy rice plants (species: Kininaze), one group of which has two rice plants. After the rice plants took, 30 barnyard grass seeds were sowed in the pot and then the herbicidal compositions of the invention (Wettable powder) and comparative compositions diluted with water of 7 ml. per pot as sh'own in the following table were dropped on the pot. Three weeks after the treatment, the number of the generation of barnyard grass, number of broad leaf weeds naturally generated and phytotoxicity on paddy rice plant were determined.

Number Number (Example 6) uoaoo l i l l Comparative composition *(PCP granule); 50

Non-treated;

1 s-(i-chlorobenzyl) N,N-diethylthidoarb'arnate: sodi N0te.-Phyt0toxicity on paddy rice plant damage; it: very slight damage; slight damage; commercially available composition containing PCEE sodium salt hydrate.

7 V Experimental Example uniformily by hand when the paddy fieldis filled with Plants to be tested: Y Water 111 depth of 3 61m t p p Wiregrass, barnyard grass, paddy rice plant (Kinmaze) Sample:

Sizes f Diameter; 5 cm (1) The herbical composition'of the present invention Compositions to be tested: 5

(1) Herbicidal composition of the invention (Exgranular P 2 (commer ample 4) clally available, granular composltlon of '25 H b d sem esit msf the invention (Ex.- PCP) 7 v e a ample 5) (3) Kasolan granular composition (commercially (3) Herbicidal composition of the invention (Exavailable, granular composition of ample 2) Determined date: July 14 (weeds within 1 n"). l

Phyto- Wei ht toxicity D Grassweed Broadleatweed otllivt I gigdd ose per an o I 10 ares, Weight, Weight, sp ikemah rice y Active ingredient sample kg. Number grams Number grams weight plant (1) Herbicide according to this invention: (Example (2) Ihara PCP granule 2 41 98.3 107 186.0 5. 4 3 7 6.2 41 72.0 8.6

(3) Kasolon granule 2 63 113.0 161 186.0 1.7

a 16 21.4 as 81.3 0

(4) Nontreated 0 94 216.0 208 321.0 9.7

NorE.-Phytot0xlcity ontriee plant, -=No damage; =I==Very slight damage; +=Slight damag.; moderate damage;

(4) Granular composition of 25% sodium salt of What is claimed is:

PCP (commercially available) 1. A method for killing grassy and broad leaf weeds Treatment: in areas containing such weeds and rise plants which com- (1) Soil containing wiregrass roots was fed in the prises applying to said areas and contacting said grassy pot and three groups of young paddy rice plants and broad leaf weeds and said rice plants with aphytotoxic (one group having two rice plants) were planted amount with respect to said weeds and non-injurious in the pot and then 20 barnyard grass seeds were amount with respect to said rice plants of composition sowed in the pot and then 24 hours later the pot comprising as an active herbicidal ingredient a thiocarwas treated with the herbicidal compositions (treatbamate having the formula;

ment before germination). (2) Wiregrass was planted in pot, in which soil was V -fil1ed with water and then the pot was treated R C S CH R' with herbicidal compositions (treatment in growin which R is selected from the group consisting of dialkyl ing stage), amino, piperidino and morpholino radicals and R is The determination was made three weeks after the selected from the group consisting of 4-chlorophenyl, 2,4- -treatment. diehlorophenyl, 3,4-diehlorophenyland bromophenyl.

Amount of active ingredients per 10 acres ---r-- Phyto- S-(t-chloro- Wiregrass treat-' Wiregrass treattoxicity Dose' Sodium benzyl-N,N- ment before ment in the Number of per salt of diethylthiogermination growing stage of barnpaddy 10 acres, PCP, earbamate, yard rice Active ingredient kg. grams grams l grass plant Herbicide according to this invention- Example4 1 150 I 1 (0.7) 3 (3.1) 4 2 300 100 0 (0) 0 0 3 450 r 150 0 (0) 0 (0) j 0 Example 5 1 250 0.5 (0. 3) 2 (2. 8) 2 2 200 140 0 (0) 1 (1.7) 0 3 300 210 0 (0) 0 (0) 0 Example2 2 100 4 (3.0) 5 (5.3) 17 6 250 l. 5 (1. 1) 3 (4. 0) 11 10 500 0 (0) 0 (0) '5 Sodium salt otPCP 1 25o s (as) a a. s 19 2 500 Ii (3. 2) 6 (6. 7) 7 3 750 4. 5 (2. 8) 5 (6. 7) 1 Non-treated 0 5 (3.7) 6 (5. 6) 18 Note.-'=growth degree of wiregrass; "=weight of living plant of wiregrass (grams); 0=no growth; 5=100% growth.

2. The method of claim 1 wherein an enough amount of said composition is applied to provide between about a 10 2 assess; entertains; Test plant: Paddy rice p1ant (spec 1 es: Norm 29) p the following formula, r I p y, I Plantes date: June 18 f s Experimental Example 6 Testarea: 1 zone: 2.5 m

. Treated date: June '23 R-( J-S CHz Cl Treatment: The composition to betested was spread in which R is selected from the group consisting of dialkyl amino and piperidino radicals.

4. The method of claim 1 wherein said thiocarbamates have the following formula:

in which R is dialkylamino radical.

5. The method of claim 1 wherein said thiocarbamates have the following formula:

in which R is dialkyl amino radical.

6. The method of claim 1 wherein said thiocarbamates have the following formula:

8. A method of killing grassy and broad leaf weeds in areas containing such weeds and rice plants which comprises applying to said areas and contacting said weeds and said rice plants within combination, an inert diluent, and as an active herbicidal ingredient, S-(4chlorobenzyl)- N,N-diethylthiocarbamate, the amount of herbicidal ingredient being a sufficient phytotoxic amount to kill the weeds but insufiicient to substantially injure the rice plants.

9. A process of selectively destroying wiregrass, barnyard grass and crabgress in a paddy field containing rice plants while not effectively damaging the rice plants which comprises contacting the rice plants and wiregrass, barnyard grass and crabgrass with a phytotoxic amount with respect to said weeds of a composition comprising S-(4- chlorobenzyl)-N,N-diethylthiocarbamate, the amount of said composition being sufficient to destroy said weeds but not sufficient to effectively damage said rice plants.

References Cited UNITED STATES PATENTS 2,992,091 7/1961 Harman et al. 71100 3,098,001 7/1963 Werres et al 424-300 3,235,355 2/1966 Klopf 71122 FOREIGN PATENTS 272,661 1/1964 Australia 71-100 995,497 6/ 1965 Great Britain 71100 JAMES O. THOMAS, Jr., Primary Examiner US. Cl. X.R. 71-94,

Inventor(s) UNITED STATES PATENT OFFICE Patent 'NO. 3,582,314

Dated June L, 1971 Makoto Konnai -et a1.

(SEAL) Attest:

Attesting Officer Column 8, line 70, "acres" should read ares 9, lines 19 to 23, the formula should appear as shown below:

Signed and sealed this EDWARD M.FLETCHER,JR.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column -S-CH Cl 16th day of May 1972.

ROBERT GOTTSCHALK Commissioner of Patents FORM F'O-105O (10-69) USCOMM-DC GOING-P69 9 0.5 GOVERNMENT PRINTING OFFICE 190 o-sss-au 

